تاثير مراحل آبياري و كاربرد نيتروژن بر عملكرد و برخي خصوصيات مرفولوژيكي

The effect of the timing of irrigatioin and nitrogen application on grain yield and some morphological traits in hybrid sunflower, cv. Golshid

In order to investigate the effect of the timing of irrigation and different nitrogen levels on grain yield and quality of sunflower crop, a field expriement was comducted using split plot design based on rardomized complete block design with 2 replications in Experimental field station, Agricultaral Research Center, Zanjan Iran in 2002 cropping season. Irrigation treatments were including: irrigation at: flowering + grain filling stages (l,), budding + flowering stages (12), budding + flowering + grain filling stages (13), and full irrigation with 8 days intervals (14) assigned to main plots and nitrogen levels of 0, 90, 180 Kg/per hectare in sub plots. Head diameter, stem diameter, plant height, number of kernel per disk and 1000 kernel weight, the percentage of unfilled kernel, biological yield and grain yield as well as water use efficiency were measured for all traits measured. Results showed that there was significant difference between irrigation treatments. The highest grain yield, 4645 kg/ha, was obtained for 14 and 180kg/ha of nitrogon. Deficit irrigation and decrease in fertilizer application had significant effect on grain yield and yield components. Deficit irrigation at vegetative and grain filling stages decreased grain yield. Increasing nitrogen application had significant effect on increasing of grain yield and biological. Deficit Irrigation had their maximum effect on 1000 kernel weight among yeild compenents. Irrigation at grain filling stages decreased 1000 kernel weight up 32%. However increasing nitrogen application had no effect on this trait. Water stress at reproductive and vegetative stages caused 20% increased unfilled kernel percentage. Difficit irrigation had no significant effect on kernel number. Application of no nitrogen, However, caused significant decrease in this trait.